The present invention relates in general to power booster amplifier units for boosting the output of a radio receiver or sound signal amplifier before application to one or a plurality of speakers and including means for varying the response in various bands of the audio or sound frequency spectrum, and more particularly to a response tracer amplifier for boosting the power between a radio receiver or audio signal amplifier system to boost the power of driving signals applied to one or more speakers, wherein individually operable controls are provided to raise and lower the output of the response tracer amplifier at a plurality of frequency bands within the audio spectrum and wherein a graphic amplifier response display is provided for visual observation by the operator to indicate visually by a continuous graph curve the amount of boosting and cutting of the signal level in a plurality of frequency bands over the sound frequency spectrum.
Heretofore, high quality amplifiers, for stereo sound systems and plural speaker sound systems and the like, either for use in the home or in automobiles or other listening spaces, have usually employed a bass control and a treble control to manually adjust the "tone" of the high quality amplifier. These controls raise and lower the output of the amplifier at the low and high frequency ends of the audio spectrum. These are provided to compensate for room acoustics, speakers that are deficient in response, tone quality discrepancies that may be caused by program source quality, or generally to please individual tastes in listening. Some amplifiers have provided more than two controls to adjust for "tone". In some instances, as many as five or ten controls have been used, each working over a small frequency range or band within the audio spectrum, thereby giving more possibilities for tone adjustment. By adjustment of the individual controls for each of the plurality of small frequency bands, the bands may be cut or boosted independently over a substantial range of decibels, to effectively modify the tonal quality of the stereo or plural speaker system, tailor the frequency response of the system to the room acoustics for more accurate reproduction, enhance the tonal characteristics and compensate for frequency aberations of the recordings, and the like. Devices have been proposed wherein the controls are in the form of linear operating slide knobs movable vertically through slots allegated to various frequency ranges, so that the pattern of the slide control knobs form a series of intermittent dots or circles at spaced locations along a path generally indicating the response curve for which the amplifier or amplifier channel has been set. However, these slide control knobs work in parallel slots which are laterally spaced from each other, so that when they are adjusted, the response of the amplifier can only be visualized by mentally drawing a line through the different positions of the controls.
An object of the present invention is the provision of a novel response tracer audio equalizer booster amplifier for plural channel stereo systems, such as radio or stereo phonograph systems, having a plurality of manually adjustable tone controls to vary the amount of boosting and cutting of the particular frequency bands associated with each of the tone controls, and wherein the tone controls are linked to a flexible rod of a response tracer display acting as a curve line on a graph to provide an observable trace display as a continuous line indicating the frequency response curve determined by the control settings.
Another object of the present invention is the provision of a graphic display response tracer audio equalizer amplifier for boosting the power output from plural channel stereo radio or amplifier systems and the like between the system amplifier and the speakers, wherein a continuous curve similar to the trace on an oscilloscope or graph is formed by a flexible rod formed into a curve in accordance with the setting of the plurality of linear operating control slide knobs or the like adjusting the response of the plurality of individual controlled frequency bands in the audio frequency range, to give an actual visual presentation of the audio response curve for which the amplifier unit has been set.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings illustrating a preferred embodiment of the invention.